Electrical machine disconnection systems

Abstract

A hybrid drive system can include a shaft, an electrical machine comprising a rotor and a stator, and a mechanical disconnect system connecting the rotor to the shaft. The mechanical disconnect system is configured to mechanically connect the rotor to the shaft in a first state and to mechanically disconnect the rotor from the shaft in a second state such that rotor does not drive the shaft or such that the rotor is not driven by the shaft. The rotor can be a permanent magnet rotor, for example.

What is claimed is: 
     
       1. A hybrid drive system, comprising:
 a shaft; and 
 an electrical machine comprising a rotor and a stator; and 
 a mechanical disconnect system connecting the rotor to the shaft, wherein the mechanical disconnect system is configured to mechanically connect the rotor to the shaft in a first state and to mechanically disconnect the rotor from the shaft in a second state such that rotor does not drive the shaft or such that the rotor is not driven by the shaft, 
 wherein the mechanical disconnect system includes a clutch mechanism configured to mechanically connect and disconnect the rotor from the shaft, wherein the mechanical disconnect system includes a gearing assembly configured to be engaged by the clutch mechanism in the first state and disengaged by the clutch mechanism in the second state to provide a geared connection between the rotor and the shaft in the first state, wherein the gearing assembly is configured to provide a freewheeling connection between the rotor and the shaft in the second state to mechanically disconnect the rotor from the shaft, wherein the gearing assembly includes a carrier shaft configured to be engaged by the clutch mechanism to stop motion of the carrier shaft in the first state, and to be dis-engaged by the clutch mechanism to allow freewheeling in the second state, wherein the carrier shaft includes a plurality of planet gears rotatably attached to the carrier shaft, wherein the shaft includes a sun gear disposed thereon meshed with the planet gears, and wherein the rotor includes a ring gear disposed thereon meshed with the planet gears. 
 
     
     
       2. The system of  claim 1 , wherein the rotor is a permanent magnet rotor. 
     
     
       3. The system of  claim 1 , further comprising one or more bearings disposed between the rotor and the shaft to allow the shaft to rotate relative to the rotor in the second state. 
     
     
       4. The system of  claim 1 , further comprising a fuel powered engine operatively connected to the shaft to drive the shaft. 
     
     
       5. A hybrid drive system, comprising:
 a shaft; 
 an electrical machine comprising a rotor and a stator; 
 a mechanical disconnect system connecting the rotor to the shaft, wherein the mechanical disconnect system is configured to mechanically connect the rotor to the shaft in a first state and to mechanically disconnect the rotor from the shaft in a second state such that rotor does not drive the shaft or such that the rotor is not driven by the shaft, wherein the mechanical disconnect system includes a clutch mechanism configured to mechanically connect and disconnect the rotor from the shaft, wherein the clutch mechanism is a face clutch mechanism configured to slidably actuate a face clutch member that rotates with the shaft to engage the rotor in the first state and to disengage the rotor in the second state to mechanically disconnect the rotor from the shaft. 
 
     
     
       6. The system of  claim 5 , wherein the rotor includes one or more rotor splines configured to engage with one or more face splines of the face clutch member in the first state. 
     
     
       7. The system of  claim 6 , wherein the face clutch member is splined to the shaft via one or more shaft splines in connection with one or more axial splines of the face clutch member. 
     
     
       8. The system of  claim 7 , wherein the face clutch mechanism includes a biasing member configured to bias the face clutch member toward the first position. 
     
     
       9. A hybrid drive system, comprising:
 a shaft; and 
 an electrical machine comprising a rotor and a stator; 
 a mechanical disconnect system connecting the rotor to the shaft, wherein the mechanical disconnect system is configured to mechanically connect the rotor to the shaft in a first state and to mechanically disconnect the rotor from the shaft in a second state such that rotor does not drive the shaft or such that the rotor is not driven by the shaft, wherein the mechanical disconnect system includes a clutch mechanism configured to mechanically connect and disconnect the rotor from the shaft, wherein the clutch mechanism includes a friction clutch mechanism having an actuator and a friction member, wherein the actuator is connected to the shaft to rotate with the shaft, wherein the friction member is configured to be pushed by the actuator to contact a rotor face to provide a frictional mechanical connection between the shaft and the rotor in the first state and to not push on the friction member in the second state to mechanically disconnect the shaft and the rotor in the second state. 
 
     
     
       10. A hybrid drive system, comprising:
 a shaft; and 
 an electrical machine comprising a rotor and a stator; and 
 a mechanical disconnect system connecting the rotor to the shaft, wherein the mechanical disconnect system is configured to mechanically connect the rotor to the shaft in a first state and to mechanically disconnect the rotor from the shaft in a second state such that rotor does not drive the shaft or such that the rotor is not driven by the shaft, wherein the mechanical disconnect system includes a clutch mechanism configured to mechanically connect and disconnect the rotor from the shaft, wherein the clutch mechanism includes a hydraulic coupling disposed around a rotor fan and a shaft fan, wherein the hydraulic coupling is configured to be sealed to the rotor and the shaft to retain a liquid therein when in a flooded state, wherein the rotor fan and the shaft fan are configured to be fluidly coupled in the flooded state such that the rotor fan drives the shaft fan, and wherein the rotor fan and the shaft fan are configured to be fluidly decoupled in a drained state.